Absorption refrigeration



Dec. 26, E950 W. G. KOGEL ABSORPTION REFRIGERATION Filed May 4, 1945 7 INVENTOR B dim ATTORN EY @atented Dec. 26, M50

UNMED STATES FATENT @FMCE.

ABSORPTION REFRIGERATKON Wilhelm Georg Kiigel, Stockholm, Sweden, as-

signor to Aktiebolaget Elektrolux, Stockholm, Sweden, a corporation of Sweden Application May 4, 1945, Serial No. 592,001 In Sweden May 9, 1944 Claims.

The invention relates to refrigeration and more particularly to a refrigeration system of the pressure equalized type. It is an object of the invention to improve the operation of a rectifier or other parts of an absorption refrigerating apparatus of the inert gas type including vessels, in which fluids of different gravity have to be transposed. A further object of the invention is to provide an improved cooling means for rectifiers.

The invention will be more fully explained with reference to embodiments diagrammatically shown in the drawing, and in this connection further characterics of the invention will be set forth.

In Fig. 1 a preferred embodiment of the invention is shown as applied to those parts of a domestic refrigerator of the pressure equalized type with which it is used. In Fig. 2 a modified embodiment of the invention is shown.

In Fig. 1 the condenser system of a continuously operating absorption refrigerating apparatus of the pressure equalized type is diagrammatically shown. This apparatus may contain as working media, water as absorbent, ammonia as refrigerant and hydrogen gas as pressure equalizing medium. The apparatus may have a liquid circulation system operated by a thermosiphon pump and a gas circulation system also arranged in a conventional manner. The condenser system consists of a U-shaped conduit, the legs of which are designated by H) and H. The vapour conduit running from the boiler of the apparatus and operating as a rectifier is designated by !2. This conduit may preferably consist of a substantially straight pipe, the upper part of which forms the rectifier and, the lower part of which forms the boiler of the apparatus and connected to the liquid heat exchanger through which poor solution fiows to the absorber. The upper end of the vapour pipe 52 is closed by a lid I 3, welded thereon and to this part of the pipe the leg to of the condenser is connected. The leg II is connected to a vessel l4, formed by a piece of pipe of substantially the same diameter as the vapour pipe i2. Both ends of said piece of pipe may be closed by lids welded thereon, or, as shown in the figures, by deforming and welding them. Further this piece of pipe or vessel I4 is welded onto the vapour pipe l2 along a common generatrix, as by welding at several points. A conduit I5 is connected to the upper part of vessel l4 and the conduit together with the U-formed pipe H), II forms the complete condenser of the apparatus,

it. Pipe it opens into a conduit I! through which the condensate from the condenser flows into the evaporator of the apparatus, not shown in the figure, and the pipe is formed to produce a liquid seal. The upper opening of said pipe i1 is connected to a pressure equalizing vessel I8 of a type known per se. Thus the pipe I! forms a draining conduit for condensate in the pressure vessel. Finally I9 indicates a ventilation conduit, through which the pressure equalizing vessel I8 communicates with the gas heat exchanger or possibly with the evaporator, not shown in the figure.

The arrangement shown in Fig. 1 operates in the following way. The boiler vapours flowing upwards through conduit l2 containgreater or smaller quantities of absorbent vapour, which should be separated before the vapours enter the condenser pipe in. This water separation is effected by cooling the vapour by heat exchange with refrigerant condensate flowing into the vessel M from the condenser pipe In, II. It is evident also that this condensate contains small quantities of absorbent, which gradually are collected at the bottom of the vessel Hi. Accordingly there would after some time appear an accumulation of absorbent which would fill a still greater part of the entire volume of the vessel it. The temperature conditions in conduit it, however, are such that the condensate of ammonia rich of absorbent and stagnant at the bottom of the vessel it slowly will get pooper of ammonia. After some time the surface layer only consists of ammonia, and this part of the liquid column in the vessel only will be effective to cool the vapours in conduit [2. The rectification produced by this surface layer will, however, be insufiicient to obtain the desired separation of absorbent. According to the present invention a continuous circulation of liquid in the vessel M is effected by heating the vessel M asymmetrically by the intermedium of the welded contact between vessel M and pipe l2 along a common generatrix at one side of the vessel only. By this asymmetrical supply of heat to the liquid column and upward flow of liquid from the bottom layer will be efiected along the heated side of the vessel, said upward fiow causing the liquid at the opposite side of the column to flow downward due to thermosyphon action. In this way a continuous circulation and mixing of liquid will take place. Accordingly the concentration of refrigerant throughout the vessel It will remain more equal-= ized with the consequence that the proportion between vapour of absorbent and vapour of refrigerant flowing through the conduit I will be the same as the proportion of these vapours appears in the vapour flowing through the pipe it. No collection of water will take place in the vessel H and the whole length of the liquid column will remain effective for the rectification of the vapours. As shown in Fig. 2, the circulation efl'ected by the asymmetrical heating of the liquid column in the vessel It may be further intensified by dividing such vessel into two chambers 22 and 23 formed by a partition 20, such chambers communicating with each other at the bottom of the vessel through an opening or aperture 2| in the partition or dividing member 20.

It will be obvious to those skilled in the art that various other changes may be made in the construction and arrangement without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawing and described in the specification but only as indicated in the appended claims.

I claim:

1. In an absorption refrigeration system of the type using a pressure equalizing gas, a condenser, a vapour conduit for supplying vapour to the condenser, a vessel in heat exchange relation with the vapour conduit and connected between the condenser and a delivery pipe to cause a continuous flow of condensate therethrough, said delivery pipe being so connected to the vessel as to maintain a body of liquid condensate in the vessel to cool and separate absorbent from refrigerant in the vapour conduit and deliver condensate above a predetermined level adjacent the top of the vessel, and said vapour conduit being disposed exteriorly of and in heat ex change relation onl with the outer peripheral surface of said vessel at one side of the latter along a vertically extending region thereof to transfer heat to the body of liquid condensate asymmetrically to cause an upward flow of liquid at said one heated side and a downward flow at the opposite side whereby to cause a continuous circulation and mixing of the liquid condensate in the vessel.

2. In an absorption refrigeration system having a generator, a condenser and conduit means for conducting to the condenser refrigerant vapor expelled from a liquid absorbent in the generator, a liquid cooled rectifier heat conductively connected to said conduit means to effect removal of absorbent vapor accompanying the expelled refrigerant vapor, said rectifier comprising a vessel connected to said condenser intermediate the ends thereof and arranged to hold a body of liquid pocketed out of circulation in the system which takes up heat of rectification and includes liquid refrigerant and also some liquid absorbent having a specific gravity greater than that of the refrigerant, and said conduit means being disposed exteriorly of and heat con-' ductively connected only to the outer peripheral surface of said vessel at one side thereof to promote upward movement of liquid at such heated side and downward movement at the opposite cooler side, thereby avoiding stratification of liquid refrigerant and liquid absorbent so that the ability of the body of pocketed liquid to take up heat of rectification will not be impaired.

3. In an absorption refrigeration system having a generator, a condenser providing an elongated path of flow for fluid, and a vapor line from said generator to said condenser, a. vessel connected in said path of flow and arranged to receive liquid formed in one part thereof, said vessel having an outlet above the bottom thereof to hold a body of such liquid and from which fluid can pass through the outlet to another part of said path of flow, and means providing a *netallic heat conductive path from the exterior surface of said vapor line only to the outer peripheral surface of said vessel at one side of the latter along a vertically extending region thereof for transferring heat from said vapor line to said vessel to asymmetrically heat the body of liquid and promote circulation of such liquid.

4. In an absorption refrigeration system having a condenser and a vapor supply line therefor, a vessel connected to receive liquid formed in the condenser and always in open communication therewith, conduit means communicating with said vessel at a region above the bottom thereof to hold a body of such liquid pocketed out of circulation in the system and from which liquid overflows by gravity into said conduit means, and said vapor supply line being disposed exteriorly of and in heat conductive relation only with the outer peripheral surface of said vessel at one side thereof to promote local circulation and mixing of the pocketed body of liquid.

5. In an absorption refrigeration system of the type using a pressure equalizing gas, a condenser, a vapor conduit for supplying vapor to the condenser, a vessel in heat exchange relation with the vapor conduit and connected between at least a part of the condenser and a delivery pipe to cause a continuous flow of condensate therethrough, said delivery pipe being so connected to the vessel as to maintain a body of liquid condensate in the vessel to cool and separate absorbent from refrigerant in the vapor conduit and deliver condensate above a predetermined level adjacent the top of the vessel, said vapor conduit being arranged in heat exchange relation with one side of said vessel to transfer heat to the body of liquid condensate asymmetrically to cause an upward flow of liquid at the heated side and a downwtard flow at the opposite side whereby to cause a continuous circulation and mixing of the liquid condensate in the vessel, said vessel having a partition therein with an opening adjacent its bottom for dividing the vessel into two connected chambers, one of said chambers being connected to receive condensate from the condenser and the other chamber being arranged in heat transfer relation with the vapor conduit.

WILHELM GEORG KtiGEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,223,752 Ullstrand Dec. 3, 1940 2,266,783 Lynger Dec. 23, 1941 FOREIGN PATENTS Number Country Date 298,574 Great Britain Oct. 3, 1929 557,311 Great Britain Nov. 15, 1943 558,338 Great Britain Dec. 31, 1943 

